The anatomy of larynx is extremely important for an anesthesiologist. A through knowledge of the anatomy of larynx is essential for mastering the skill of intubation with a tracheal tube.
Larynx is the organ of voice extending from the root of the tongue to trachea and lies opposite C3 to C6 vertebrae.
The distance between teeth and vocal cords is 12 to 15 cms and the distance between vocal cords and carina is 10 to 15 cms.
The larynx consists of 3 paired cartilages namely Arytenoid, Corniculate and Cuneiform and three unpaired cartilages namely Thyroid, Cricoid and Epiglottis.
The glottis is the narrowest part in adults while Subglottis (Cricoid ring) is the narrowest part in children up to the age of 5years. That is why during intubation in children uncuffed endotrachea1 tubes should be used. This is because the anatomy of larynx in children is different from that of adults. The larynx is also more prone to develop oedema in children.
Anatomy of Larynx : Nerve supply of larynx:
The nerve supply of larynx is by two important nerves.
All muscles of the larynx are supplied by recurrent laryngeal nerve except cricothyroid which is supplied by external branch of superior laryngeal nerve. This is the motor supply.
Sensory supply of larynx:
The sensory supply of larynx up to vocal cords is by the internal branch of superior laryngeal nerve and below the vocal cords is by the recurrent laryngeal nerve.
Anatomy of Larynx : Blood supply of larynx:
The blood supply of larynx is by the laryngeal branches of superior and inferior thyroid arteries.
This is the basic knowledge about the anatomy of larynx which an anaesthetist should always remember.